OS 10.4 - Tiger Server Firewall/Nat Frustration

I'm trying to replace a Redhat 9 Linux box I have doing my firewall/nat for my network sitting behind it using iptables.

I have used the Lynda.com movie's to setup the Tiger sever and everything has worked great until now. The movies are useless on firewall/nat and I have been unable to find detailed documentation on firewall/nat for Tiger Server.

In the setting for firewall, under the Services, I have the Radio button checked for "Allow only traffic for 'any' on these ports" set.

(There are several other unrelated boxes checked for other ports I don't mention here)

These are the only mail related boxes I can check. I save this config and start the firewall service and neither POP or SMTP transaction can take place on the internal clients. When I stop the service, check the Radio button "Allow all traffic for 'any'" and restart the firewall service, then mail transactions take place.

The iTunes Radio/Store functionality does not work with either setting, So I can't help but wonder if the NAT is not working correctly. I will send the to APPLE to see if I can get a response.